Belt tightening apparatus



May 23, 1933. c DUNCAN 1,911,071

BELT TIGHTENING APPARATUS Filed Sept. 8;, 1930 ATTOP/VE/S Patented May 23, 1933 UNITED STATES CLAUDE DUNCAN, or rinnivronn, CALIFORNIA BELT TIGHTENING APPARATUS Application filed September 8, 1930. Serial in. 480,421.

This invention relates to an improved belt stretching and tightening device, and has for one of its principal objects the provision of means for use in shops, factories, packing plants and the like wherever belts made of leather, canvas, or similar material are employed either for driving machinery or as part of conveyor equipment.

One of the important objects of this invention is to provide means for conveniently retaining a belt in position upon a set of pulleys or other apparatus while a section of the belt is being removed to take up for slack caused by stretching.

Another important object of this invention resides in the provision of means for tightening or stretching the belts and also for holding the main portion of a belt tight over its rollers or pulleys while a cutting and relacing operation is being performed, all this without the necessity of removing the belt from the machine.

Another and still further important object of this invention is to provide means for quickly and satisfactorily removing a portion of a belt from machinery or the like for tightening the same and for as quickly and conveniently re-uniting the severed ends of the belt in a desirable manner and with a minimum error in adjustment.

Other and further important objects of the invention will be apparent from the disclosures in the accompanying drawing and specification.

The invention, in a preferred form, is shown in the drawing and hereinafter more fully described.

In the drawing:

Figure 1 is a top plan view of the improved belt stretcher of this invention, showing the same in position on a belt.

Figure 2 is a side elevation of the belt stretcher.

As shown in the drawing:

The reference numeral 10 indicates generally a belt or the like used for machinery or conveyor apparatus, and which is shown as having considerable slack 12 therein adapted to be taken up by the improved device of this invention, while at the same time the remaining portions of the belt are maintained tightly in desired position whereby the severed ends of the belt adjacent the slack 12 can be conveniently and readily re-united after the slack has been removed and with a minimum error in adjustment.

The invention resides principally in a pair of clamps, one at each end of the device, each pair of clamps comprising a fixed member 12 and a removable cooperative member 1 1, each of these members being of a sufficient length to extend completely across the belt, and being mounted in a toggle-link support as best shown in Figure 2, the same comprising a rear member 16, to the upper and lower ends of which is pivotally mounted a lower link 18 and an upper link 20, these links being adapted to contact with the ends of the members 12 and 1 1 respectively, and being themselves pivotally at tached at their forward ends to additional links 22 and 24 respectively, the forward ends of which are pivotally connected together and also to pulley wheel supports or the like 26 in each of which is mounted a pulley wheel 28. The pulley wheels 28 are mounted in only one set of the clamping elements positioned atone end of the device, as shown'in the figures, while the clamping elements and toggle links are duplicated at H when the apparatus is in operation, the shaft having drums 32 and 34 afiixed thereon whereby rotation of the shaft will rotatethe drums.

Ropes or the like 36 are mounted on the drums for reeling thereon, the ropes being first attached at one free end 38 to the shaft or the like 46 which has a spring-pressed pawl 48 mounted thereon, which contacts with the teeth of the ratchet wheel, thereby assuring that the same is moved in one direction only upon reciprocation of the handle 46 about its pivot point on the shaft 30.

Another similarly acting pawl 50is provided for the ratchet wheel 42 whereby the drums 32 and 34 will be held in position against rotation, while the handle 16 is being moved forwardly for another return stroke during which the pawl 48 comes into play, and acts to rotate the shaft 30, thereby winding the rope 36 around the drums 32 and 34,, and taking up the slack in the belt in an obvious manner.

It will be noted that on account of the toggle construction of the links 18 to 2% inclusive, the device will be positively maintained in position on the belt at all times during operation thereof, and slipping is absolutely prevented. lVhen the clamping members 12 and 14 are properly positioned on the belt, a straight pull results which eliminates any undesirable angularity in the resultant cut portion.

Obviously, the slack 12 in a belt 10 can be readily taken up by means of this device and removed, whereupon the belt can again be conveniently joined together by lacing or the like, and a positive adjustment so far as desired tightness is concerned will be accomplished.

A single apparatus of this sort may be made adaptable for use with belts of varying widths simply by using longer cross members12 and 14, and by slidably keying .the drums or spools 32 and 34 on the shaft 30 so that these larger cleats may be accommodated. lVire rope or other cable may be used instead of hempen rope, and the inside faces of the cleats may be provided with corrugations or other gripping surfaces. However, the toggle action is such that the gripping action increases as the tension is applied, thereby practically eliminating any possibility of slippage.

After the re-lacing has been accomplished, the device may be readily removed by re leasing the ratchet pawl 50, pushing up on the end clamps, and removing the top cleats, whereupon the apparatus may be slipped out from under the belt.

I am. aware that many changes may be made and numerous details of construction varied throughout a wide range without departingfrom the principles of this invention, and I, therefore, do not purpose limiting the patent granted hereon otherwise than as necessitated by the prior art.

I claim as my invention:

A belt stretched and tightener, including a pair of clamps adapted to be removably applied to two portions of a belt, toggle links extending forwardly of each clamp for belt gripping purposes, and means for drawing the clamps together when in position on the belt, said means comprising pulley wheels horizontally mounted on one set of clamps at the ends of the toggle links, a rotatable shaft mounted in the ends of the toggle links of the other clamp said shaft comprising a pivot for the links, drums on the shaft, and ropes attached to the shaft passing over the pulley wheels and adapted to be reeled onto the drums, together with an operating lever for rotating the shaft and drums, and pawl and ratchet connections between the operating lever and the shaft, and a further pawl and ratchet connection between the shaft and the belt tightener clamp for retaining the shaft in rope tensioned position.

In testimony whereof I affix my signature.

CLAUDE DUNCAN. 

